Conventional gas turbine engines comprise a compressor section and a turbine section. The compressor section may include a low pressure compressor and a high pressure compressor. The turbine section may include a low pressure turbine and a high pressure turbine. The rotating portions of the compressors and turbines form rotors comprising one or more rotor disks coupled to each other to form a rotor disk stack. As the rotor disk stack rotates within the gas turbine engine at high speeds, the rotor may be rotationally balanced to reduce vibration. At least one rotor disk in the rotor disk stack may include a flange portion to which one or more balance weights is coupled, thereby balancing the rotor disk stack. However, the rotor disk stack may be subject to oil collection due to its proximity to a bearing compartment within the gas turbine engine. Oil collection by the rotor disk stack is desirably minimized for fire safety.
Conventional methods for minimizing oil collection in and around the rotor disk stack have included incorporating a drain hole into the flange portion thereof or scalloping the flange portion with curved notches, but these conventional methods may structurally weaken the rotor disk stack.